|
|
|
#16
07-05-2014, 10:21 AM
|
||||
|
||||
|
Thanks guys! And thanks for the offer of a circuit breaker. It's seems to be working OK now, but I'll let you know if that changes.
I hope to recap the vertical and horizontal boards by next weekend. 
|
|
#17
07-06-2014, 02:16 PM
|
||||
|
||||
|
Found the time yesterday to recap the horizontal and vertical boards, plus several around the HOT, damper and HV regulator. There are several oddball values that I didn't have on hand that I'll order and replace on the next round.
  The recapping improved things significantly, and I was easily able to get good screen geometry (the vertical linearity had been quite bad).  I also decided to measure the 6DQ5 cathode current and double check the HV. The cathode current measured almost 230 ma  And when I tried to adjust the coil, the core wouldn't budge. I feared that the slug had been cracked previously, but close inspection revealed that was intact. I applied gentle heat with a hair drier and I was very relieved that the core began to turn freely, yay!I was able to get a nice sharp dip at about 192 ma. Not as low as I'd like, but a lot better than it was and below the specified 200 ma maximum.   Now I feel like I can watch the set without fear of it self-destructing. The picture looks quite good now.   It will probably be a while until I do more work on the chassis. I plan to do some work cleaning up the faux wood grain finish. Thanks for the help and encouragement!
|
|
#18
07-06-2014, 03:25 PM
|
|||
|
|||
|
one thing to consider is the line voltage as well, I found that adj to 117vac got me to under 180ma IIRC. Even at that it still gets warmer than I like, but guess that is just the way it is. Pic looks great
|
|
#19
07-07-2014, 01:19 PM
|
||||
|
||||
|
Thanks Dave, that's a good suggestion. My line voltage has been running about 122V. I always use an "RCA Color Volt" constant voltage transformer with my CTC-7 which keeps it at 117V and I do think it runs cooler.
|
|
#21
07-08-2014, 08:55 AM
|
||||
|
||||
|
Quote:
I imagine its a classic "Magnetic Conditioner" like was used on computer and medical equip in the 70s and into the 80s, but with a name like "Color Volt" I wouldn't bet on anything, honestly.
|
|
#22
07-08-2014, 11:19 AM
|
||||
|
||||
|
I'll have to post a picture of the Color Volt (I forget if they spelled it as one word or two). I think it was made for RCA by the Sola Corporation which sold their own line of Sola Volt CVT's (constant voltage transformers). Here's a link to a used one forsale: http://www.radio-mart.net/Sola-Const...ansformer.html
If you Google CVT you can read all about how they work. Since they intentionally drive the transformer core into saturation, they tend to be quite noisy (loud hum) and generate quite a bit of heat. I keep mine behind the set so the noise isn't too much of an issue. -Clark
|
|
#23
07-08-2014, 11:39 AM
|
||||
|
||||
|
Wow, that TV is really shaping up. A CTC-11 makes an awfully nice picture when it's working right.
Phil Nelson Phil's Old Radios http://antiqueradio.org/index.html
|
|
#24
07-08-2014, 01:10 PM
|
||||
|
||||
|
Looking great, Clark.
|
|
#25
07-08-2014, 03:05 PM
|
||||
|
||||
|
RE: Sola transformer - I believe that is called a saturation transformer.
That looks Great! makes me want to drop everything and work on my CTC11A
__________________
"When resistors increase in value, they're worthless" -Dave G
|
| Audiokarma |
|
#26
07-08-2014, 03:31 PM
|
||||
|
||||
|
Thanks for the nice comments! This one turned out to be pretty easy to resurrect. I wish they were all this easy! (Or maybe not, since trouble shooting is half the fun
 ) Since I took the photos, I degaussed the CRT which cleared up a minor purity issue. I haven't touched the convergence and I'm inclined not to since it's really pretty good. I am now running it on a variac set to 117V which is the input voltage specified by RCA.-Clark Last edited by IsthmusTV; 07-09-2014 at 11:09 AM. Reason: fixed typo
|
|
#28
07-08-2014, 06:57 PM
|
||||
|
||||
|
Quote:
Phil Nelson
|
 |
|
|
Linear Mode
